In a step for manufacturing semiconductor devices, a film to be processed is first formed on the substrate, such as a semiconductor wafer (that will be merely referred to as “the wafer”) or the like, and then a resist film is formed, in a predetermined pattern, on the film to be processed. Thereafter, a process, such as the etching process, ion implantation or the like, is provided to the film to be processed, with the resist film being used as a mask. Then, after such a process is performed, the resist film that is no longer required is removed from the wafer.
As a method for removing the resist film, an SPM process is well known. This SPM process is performed by heating an SPM (Sulfuric Acid Hydrogen Peroxide Mixture) liquid that is obtained by mixing sulfuric acid with aqueous hydrogen peroxide, and then supplying the so-heated SPM liquid to the resist film.
Generally, in the SPM process, the SPM liquid heated to a high temperature is discharged toward the wafer. Therefore, in some cases, the SPM liquid is vaporized and thus fumes are generated. In such a case, the fumes are spread in a wide range in a chamber of a resist removing apparatus, thus leading to contamination of an inner wall of the chamber and parts provided in the chamber. Further, such fumes may cause contamination of the wafer. However. It should be noted that such a problem may also be caused by using any other chemical liquid than the SPM liquid.
In order to prevent the fumes from being spread in the wide range in the chamber and prevent the contamination of the inner wall of the chamber and the parts provided in the chamber, one resist removing apparatus is proposed in JP2007-35866. This resist removing apparatus includes a substrate holding unit configured to hold the wafer, a shielding wall provided for surrounding the wafer held by the substrate holding unit and having an opening positioned above the wafer, a cover located above the shielding wall, and a nozzle that is laterally inserted through a gap provided between the shielding wall and the cover and configured to discharge the SPM liquid toward the wafer. According to the resist removing apparatus disclosed in the JP2007-35866, the shielding wall and cover can respectively serve to prevent the fumes from being widely spread in the chamber.